Hardware Reference
In-Depth Information
run. The next line is the
avrdude
command to upload your hex file. You'll need to install
avrdude
with the following command:
sudo apt-get install avrdude
Then, to run the script, perform the following:
sudo ./upload Blink.cpp.hex
Prior to flashing an Arduino sketch, you must have a sketch to flash. Depending on your
development preference, there are several options. You can build your AVR program on
the BBB with a makefile and
gcc-avr
. Or you can build your program with Atmel's free
AVR Studio or the Arduino IDE. Whichever way you choose, you need to find the com-
piled
hex
file and download it to the BBB using
sftp
or a similar tool.
Before you upload sketches to the CryptoCape's ATmega, you'll need to perform one very
important step: you need to attach jumpers to the two
Program Jumper
pins. Without the
jumpers, the ATmega is not electrically connected to the BBB serial lines. This is a secur-
ity feature. Using the Arduino bootloader, it is possible to upload
hex
files using serial
UART. Thus, with the jumpers installed, the sketch on the CryptoCape's ATmega can al-
ways be modified. Now imagine if the BBB was inflicted with malware, but had the
jumpers removed. This malware can't change the software on the ATmega. It can still do
lots of other nasty things including resetting the ATmega, but it can't upload new firmware
unless the jumpers are attached.